The project is a physiochemical study of the structure of the E. coli ribosome. Since the ribosome is a complex of approximately 58 discrete chemical entities including both RNA and protein, it is proposed that the main interactions stabilizing the structure be located, evaluated and related, perhaps, to function. In general, this shall be accomplished by isolating and characterizing the components that comprise the ribosome. After having knowledge regarding the solution behavior of pure isolated members, solution mixtures of the macromolecules will be assessed for interactions between the components. Studying these interactions as a function of solvent conditions will enable one to ascertain the nature of the forces involved as well as the magnitude of contribution to the overall stabilization. The techniques employed to measure the interactions will be analytical ultracentrifugation sedimentation equilibrium and velocity as well as analytical molecular sieve chromatography and UV difference spectroscopy.